1. Field of the Invention
The invention relates to a tunnel baking oven.
2. Background Art
Continuous baking ovens, also designated as tunnel ovens, are generally known in baking technology. They have an inlet station and an outlet station, between which a continuously circulating belt is disposed, the upper strand of which is led through a continuous baking chamber, conveying the dough pieces there-through. A tunnel baking oven of the generic type may have only a single hearth or several hearths one above the other. The baking oven has an energy cell, by means of which to heat the baking chamber. For several reasons, in particular for constructional reasons, the width of these tunnel baking ovens, and in particular of the baking conveyor belts, is restricted. On the other hand, there are cases when a throughput is desired which is so high that overwide ovens are desirable, an arrangement of several hearths one above the other not being feasible for various reasons.
It is an object of the invention to embody a tunnel baking oven which offers an overwide design and various possibilities of employment accompanied with the simplest structure.
This object is attained in a tunnel baking oven comprising at least two oven trains, which are disposed side by side and parallel to a direction of throughput and which have an inlet station and an outlet station; a baking chamber, which runs from the inlet station as far as to the outlet station in each oven train; at least one energy cell heating the baking chambers; and a continuous baking conveyor belt, which runs from the inlet station as far as to the outlet station in each baking chamber, the baking conveyor belts being drivable in the same direction at the same rate as well as at different rates. Simplistically, the tunnel baking oven according to the invention comprises two tunnel ovens side by side, the oven trains, each having a baking conveyor belt of its own. Due to the fact that it is possible to operate the baking conveyor belts at an identical speed or each at different speeds, equal or varying baking times may lead to correspondingly identical or varying baking results. When an intermediate wall is provided between the baking chambers, and in particular when this intermediate wall is adjustable for change between a first position in which the baking chambers are connected with each other and a second position in which the baking chambers are separated from each other, this may help to set different baking atmospheres and temperatures in the two baking chambers, which may however also be equalized.
In keeping with an advantageous development, it is provided that only one oven train is equipped with an energy cell, and that the baking chamber of the other oven train is connectable to, and disconnectable from, the energy cell; and in particular that each oven train is equipped with a heating-gas flow pipe with the heating-gas flow pipes of both oven trains being connectable to, and disconnectable from, each other; and that each oven train is equipped with a heating-gas return pipe with the heating-gas return pipes of both oven trains being connectable to, and disconnectable from, each other. This ensures that a single energy cell will be sufficient to heat a single baking chamber or both baking chambers. Equal or different baking conveyor belt speeds are attained in keeping with the embodiment according to which each baking conveyor belt is led along a driving roller, with each driving roller being drivable by a driving motor and the driving rollers being coupled with each other; and according to which an engaging and disengaging coupling is provided between the driving rollers; and according to which the driving motors are electrically coupled with each other.
Further features, details and advantages of the invention will become apparent from the ensuing description of an exemplary embodiment, taken in conjunction with the drawing.